What is the Harvest Moon and Why Is It Late This Year?

On Thursday, October 5, the moon will once again be full, with all of its sunlit side visible from Earth. Usually, October's full moon is known as the Hunter's Moon, in honor of deer-hunting season. But this year, thanks to a quirk in celestial schedules, October's full moon is instead the Harvest Moon.

North America's moon nicknames are adapted from American Indian terms for the moons. Tribes tied each lunar cycle to what was happening in the natural world. Most of the names now in popular use were coined by members of the Algonquin tribes, who once lived throughout New England and the Great Lakes area.

Other tribes across the continent have other nicknames for the moons—October names include "moon when the wind shakes off the leaves" among the Lakota people and "the moon the birds fly south" among the Cree people, according to Phil Konstantin, a retired NASA scientist with Cherokee roots who collects American Indian celestial terms.